package com.axujie.tlgypt.service.utils;
import java.net.URLDecoder;
import java.net.URLEncoder;

import java.security.MessageDigest;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;


/**
 * 通过3-DES算法对字符串进行加密解密类
 */
public class DES3Encrypt {
    
    
    /**
    * 对字符串进行3-DES加密
    * @param value 加密的字符串
    * @param key 密钥
    * @return 加密后的字符串
    */
    public static String encrypt(String value,String key) {
        DES3Encrypt ten = new DES3Encrypt();
        return ten.get3DESEncrypt(value,key);
    }
    
    /**
     * 对字符串进行3—DES解密
     * @param value 解密字符处
     * @param key 解密key
     * @return
     */
    
    public static String decrypt(String value,String key){
        DES3Encrypt ten = new DES3Encrypt();
        return ten.get3DESDecrypt(value,key);
    }
    
    /**
     * 进行MD5加密
     * @param  strSrc 原始的SPKEY
     * @return  byte[] 指定加密方式为md5后的byte[]
     */
    private  byte[] md5(String strSrc) {
        byte[] returnByte = null;
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            returnByte = md5.digest(strSrc.getBytes("GBK"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return returnByte;
    }


    /**
     * 得到3-DES的密钥匙
     * 根据接口规范，密钥匙为24个字节，md5加密出来的是16个字节，因此后面补8个字节的0
     * @param  spKey 原始的SPKEY
     * @return  byte[] 指定加密方式为md5后的byte[]
     */
    private byte[] getEnKey(String spKey) {
        byte[] desKey = null;
        try {
            byte[] desKey1 = md5(spKey);
            desKey = new byte[24];
            int i = 0;
            while (i < desKey1.length && i < 24) {
                desKey[i] = desKey1[i];
                i++;
            }
            if (i < 24) {
                desKey[i] = 0;
                i++;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return desKey;
    }


    /**
     * 3-DES加密
     * @param src 要进行3-DES加密的byte[]
     * @param  enKey 3-DES加密密钥
     * @return  3-DES加密后的byte[]
     */
    public

    byte[] Encrypt(byte[] src, byte[] enKey) {
        byte[] encryptedData = null;
        try {
            DESedeKeySpec dks = new DESedeKeySpec(enKey);
            SecretKeyFactory keyFactory = 
                SecretKeyFactory.getInstance("DESede");
            SecretKey key = keyFactory.generateSecret(dks);
            Cipher cipher = Cipher.getInstance("DESede");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            encryptedData = cipher.doFinal(src);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encryptedData;
    }


    /**
     * 对字符串进行Base64编码
     * @param src 要进行编码的字符
     * @return  进行编码后的字符串
     */
    public  String getBase64Encode(byte[] src) {
        String requestValue = "";
        try {
            BASE64Encoder base64en = new BASE64Encoder();
            requestValue = base64en.encode(src);
            //System.out.println(requestValue);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return requestValue;
    }


    /**
     * 去掉字符串的换行符号
     * base64编码3-DES的数据时，得到的字符串有换行符号
     * ，一定要去掉，否则就会出问题。
     */
    private  String filter(String str) {
        String output = null;
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            int asc = str.charAt(i);
            if (asc != 10 && asc != 13)
                sb.append(str.subSequence(i, i + 1));
        }
        output = new String(sb);
        return output;
    }


    /**
     * 对字符串进行URLDecoder.encode(strEncoding)编码
     * @param src 要进行编码的字符串
     * @return  String 进行编码后的字符串
     */
    public String getURLEncode(String src) {
        String requestValue = "";
        try {

            requestValue = URLEncoder.encode(src,"GBK");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return requestValue;
    }


    /**
     * 3-DES加密
     * @param  src 要进行3-DES加密的String
     * @param  spkey 分配的SPKEY
     * @return  3-DES加密后的String
     */
    public String get3DESEncrypt(String src, String spkey) {
        String requestValue = "";
        try {

            //得到3-DES的密钥匙
            byte[] enKey = getEnKey(spkey);
            //要进行3-DES加密的内容在进行\"UTF-16LE\"取字节
            byte[] src2 = src.getBytes("UTF-16LE");
            //进行3-DES加密后的内容的字节
            byte[] encryptedData = Encrypt(src2, enKey);

            //进行3-DES加密后的内容进行BASE64编码
            String base64String = getBase64Encode(encryptedData);
            //BASE64编码去除换行符后
            String base64Encrypt = filter(base64String);

            //对BASE64编码中的HTML控制码进行转义的过程
            requestValue = getURLEncode(base64Encrypt);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return requestValue;
    }


    /**
     * 对字符串进行URLDecoder.decode(strEncoding)解码
     * @param src 要进行解码的字符串
     * 
     * @return  进行解码后的字符串
     */
    public String getURLDecoderdecode(String src) {
        String requestValue = "";
        try {

            requestValue = URLDecoder.decode(src,"GBK");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return requestValue;
    }


    /**
     * 
     *进行3-DES解密（密钥匙等同于加密的密钥匙）。 
     * @param byte[]  src 要进行3-DES解密byte[] 
     * @param   String spkey分配的SPKEY
     * @return  String 3-DES解密后的String
     */
    public String deCrypt(byte[] debase64, String spKey) {
        String strDe = null;
        Cipher cipher = null;
        try {
            cipher = Cipher.getInstance("DESede");
            byte[] key = getEnKey(spKey);
            DESedeKeySpec dks = new DESedeKeySpec(key);
            SecretKeyFactory keyFactory = 
                SecretKeyFactory.getInstance("DESede");
            SecretKey sKey = keyFactory.generateSecret(dks);
            cipher.init(Cipher.DECRYPT_MODE, sKey);
            byte ciphertext[] = cipher.doFinal(debase64);
            strDe = new String(ciphertext, "UTF-16LE");
        } catch (Exception ex) {
            strDe = "";
            ex.printStackTrace();
        }
        return strDe;
    }


    /**
     * 3-DES解密
     * @param src 要进行3-DES解密的String
     * @param  spkey 分配的SPKEY
     * @return  String 3-DES加密后的String
     */
    public  String get3DESDecrypt(String src, String spkey) {
        String requestValue = "";
        try {

            //得到3-DES的密钥匙

            //URLDecoder.decodeTML控制码进行转义的过程
            String URLValue = getURLDecoderdecode(src);

            //进行3-DES加密后的内容进行BASE64编码

            BASE64Decoder base64Decode = new BASE64Decoder();
            byte[] base64DValue = base64Decode.decodeBuffer(URLValue);

            //要进行3-DES加密的内容在进行\"UTF-16LE\"取字节

            requestValue = deCrypt(base64DValue, spkey);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return requestValue;
    }

}

